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Evaluation of depolarization changes during acute myocardial ischemia by analysis ofQRS slopes

Ringborn Michael Romero Daniel Pueyo Esther Pahlm Olle Wagner Galen S LagunaPablo Platonov PyotrPublished inJournal of Electrocardiology

DOI101016jjelectrocard201103005

Published 2011-01-01

Link to publication

Citation for published version (APA)Ringborn M Romero D Pueyo E Pahlm O Wagner G S Laguna P amp Platonov P (2011) Evaluationof depolarization changes during acute myocardial ischemia by analysis of QRS slopes Journal ofElectrocardiology 44(4) 416-424 DOI 101016jjelectrocard201103005

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Download date 26 Aug 2018

1

EVALUATION OF DEPOLARIZATION CHANGES DURING ACUTE MYOCARDIAL

ISCHEMIA BY ANALYSIS OF QRS SLOPES

Michael Ringborn MD abc Daniel Romero MS de Esther Pueyo PhD de Olle

Pahlm MD PhD bf Galen S Wagner MD g Pablo Laguna PhD de and Pyotr G

Platonov MD PhD ab

a Department of Cardiology Lund University Lund Sweden b Center for Integrative

Electrocardiology at Lund University (CIEL) Lund Sweden c Thoracic Center

Blekingesjukhuset Karlskrona Sweden d Communications Technology Group I3A

University of Zaragoza Spain e Centro Investigacioacuten Biomeacutedica en Red (CIBER) de

Bioingenieria Biomateriales y Nanomedicina Zaragoza Spain f Department of

Clinical Physiology Lund University Lund Sweden g Duke University Medical

Center Durham NC

Running title QRS slope changes during coronary artery occlusion

This study was supported by American Heart Association Durham North Carolina

USA (account 5-21628) the Southern Healthcare Region Lund Sweden Blekinge

scientific council Sweden Donation funds at Lund University Hospital projects

TEC2010-19410 and TEC2010-21703-C03-02 from MICINN Spain project PI14409

from Gobierno de Aragoacuten Spain and Grupo Consolidado GTC refT30

Corresponding author

Michael Ringborn MD Thoracic Center Blekinge Hospital

SE- 371 85 Karlskrona Sweden

Phone +46 455 73 10 00 Fax number +46 455 73 65 80

2

e-mail michaelringbornyahoocom

ABSTRACT

Objective This study evaluates depolarization changes in acute myocardial

ischemia by analysis of QRS slopes

Methods In 38 patients undergoing elective percutaneous coronary intervention

(PCI) changes in upward slope between Q and R waves (US) and downward slope

between R and S waves (DS) were analyzed In leads V1-V3 upward slope of the S-

wave (TS) was additionally analyzed Ischemia was quantified by myocardial

scintigraphy Also conventional QRS and ST measures were determined

Results QRS slope changes correlated significantly with ischemia (for DS r=071

plt00001 for extent and r=073 plt00001 for severity) Best corresponding

correlation for conventional ECG parameters was sum of R-wave amplitude change

(r=063 plt00001 r=060 plt00001) and sum of ST-segment elevation (r=067

plt00001 r=073 plt00001) Prediction of extent and severity of ischemia increased

by 122 and 71 by adding DS to ST

Conclusions DS correlates with ischemia and could have potential value in risk

stratification in acute ischemia in addition to ST-T analysis

Key words QRS slope myocardial ischemia depolarization changes ST-segment

deviation PCI

3

INTRODUCTION

Analysis of the standard 12-lead ECG is most valuable in the clinical evaluation of

suspect acute myocardial infarction (AMI) both in pre-hospital and in-hospital setting

In addition to ischemia detection the ECG recorded in the acute phase of myocardial

infarction (both ldquosnapshotrdquo ECG as well as ECG retrieved from a monitoring system)

can also add further information about prognosis and risk stratification ie

possibilities for improved early triage and tailoring of the acute treatment for better

outcome To achieve that other information within the ECG signal than the

conventional ST-T analysis needs to be evaluated Myocardial ischemia in more

severe stages also affects the depolarization phase Some of these changes are

considered to represent already necrotic areas (Q waves) but other potentially

reversible changes in the QRS complex also appear although they are less well

understood and are usually not considered for clinical decision making Earlier

studies on depolarization changes during ischemia due to acute coronary occlusion

have considered QRS prolongation (1-5) amplitude changes of the R- and S-waves

(4 6 7) ldquodistortionrdquo of the terminal part of the QRS complex (8-12) as well as

changes in the high-frequency components of the QRS complex (13-15)

Prolongation of the QRS complex has been described as a marker of more severe

ischemia with slow conduction both in animal studies and in humans during

percutaneous coronary intervention (PCI) and AMI (1 4-6 16) Also in a large cohort

of ST-elevation myocardial infarction (STEMI) patients Wong et al reported an

independent positive relationship between QRS duration on admission ECG and 30-

day mortality for anterior infarct location (2 3) Prolongation of the QRS duration is

4

however difficult to determine correctly since ST elevation commonly obscures the

delineation between the end of the depolarization and beginning of the repolarization

In the Sclarovsky-Birnbaum ischemia grading system distortion of the terminal part of

the depolarization in addition to pronounced ST elevation (grade 3 ischemia) has in

several studies been found to be a sign of more severe myocardial ischemia and

predict larger infarct size lesser degree of ST-segment resolution impaired

microvascular patency and worse clinical outcome after revascularization by either

thrombolysis or primary PCI (8-11) These changes have been reported to be

stronger predictors of clinical outcome than ST measures alone This ischemia

grading system or any other method of assessing depolarization changes have not

however been implemented in clinical practice To facilitate clinical implementation a

more robust and clinically feasible method of QRS complex analysis is needed as

well as better understanding of the pathophysiological bases of the depolarization

changes

In 2008 Pueyo et al proposed a method for evaluation of depolarization changes by

analyzing the slopes of the QRS complex upward slope between Q and R waves

(US) and downward slope between R and S waves (DS) (17) During coronary artery

occlusion by PCI the QRS slopes became considerably less steep than in the control

situation in particular for the DS as a combined result of both changes of the QRS

amplitude and duration This analysis method has now been developed further and

has become more robust showing very low intra-individual variation in a control

situation (18) We have furthermore introduced calculation of the most terminal slope

for leads with an S wave (TS) In the same ischemia model (during elective PCI) but

in a larger study population we showed that changes of the DS among the 12

standard ECG leads are generally more pronounced than US changes regardless of

5

coronary vessel occluded and that this measure performs equally to TS (in

applicable leads V1-V3 during anterior ischemia) (18) Left anterior descending artery

(LAD) occlusions showed larger changes of the slopes than did right coronary artery

(RCA) and left circumflex (LCX) occlusions In previous studies changes of the QRS

slopes have not been correlated to the actual amount of ischemia or compared to

other conventional ECG indices of ischemia

Myocardial perfusion scintigraphy (MPS) is a reliable method of detecting and

quantifying myocardial ischemia induced by elective PCI (19 20) The general

objective of this study was to further evaluate QRS slope changes during ischemia

induced by elective PCI of LAD RCA and LCX quantified by MPS Specific aims

were to test

1 If the amount of QRS slope changes correlates to the extent and severity of

ischemia as determined by MPS and compare the correlation to that of

conventional depolarization parameters (R-wave amplitude change and QRS

prolongation)

2 If QRS slope changes add information to conventional ST-elevation analysis in

the correlation to the extent and severity of ischemia

3 If the slope changes hold spatial information regarding coronary occlusion site

METHODS

Study population

A total of 38 consecutive patients (age 63plusmn12 (33-80) 25 (66) men) admitted to the

Charleston Area Medical Center WV USA for prolonged elective PCI (occlusion time

49plusmn09 (24-73) min) due to stable angina pectoris were considered for this study

6

The distribution of coronary artery occluded was LAD 8 LCX 9 and RCA 21 The

study was approved by the local Investigational Review Board and informed consent

was obtained from each patient prior to enrolment The inclusion criteria were No

evidence of an acute or recent myocardial infarction intraventricular conduction delay

with QRS duration ge120 msec (including RBBB and LBBB) pacemaker rhythm low

voltage atrial fibrillationflutter any ventricular rhythm at inclusion or during the PCI

procedure and appropriate signal quality Balloon inflation was maintained for ge 5

minutes whenever clinically feasible For all 38 patients myocardial scintigraphic

imaging was additionally performed during the PCI and as a control the following day

to provide a means of quantifying the ischemia

ECG Acquisition

With the patient resting in the supine position in the cath lab a continuous 12-lead

ECG recording was performed starting prior to the PCI procedure and acquired

continuously during the PCI to approximately 4 minutes after balloon deflation The

part of the recording corresponding to the period of occlusion was extracted for off-

line analysis For the limb leads Mason-Likar electrode configuration was used to

minimize the noise level (21) The precordial leads V1-V6 were obtained using the

standard electrode placements The signals were digitized at a sampling rate of 1

kHz with an amplitude resolution of 06 microV If more than one balloon inflation was

performed during the procedure only the first one was considered in order to avoid

possible bias due to either ischemia-induced collateral recruitment and

preconditioning within the area of a previous inflation or persistent ischemia in the

myocardium

7

Preprocessing and normalization

The ECG for each patient was preprocessed by QRS detection normal beat

selection baseline drift attenuation via cubic spline interpolation and wave

delineation using a wavelet-based technique as previously described (17 18) To

reduce and compensate for low frequency noise such as respiration modulations of

the depolarization phase a normalization procedure was applied to all the ECG

signals prior to the evaluation of the indices (18)

QRS slope analysis

Three QRS slopes were determined in each beat

1 US The upward slope of the R wave

2 DS The downward slope of the R wave

3 TS The upward terminal slope of the S wave (only in leads V1-V3)

The different slopes are shown in Figure 1a The successive steps of slope analysis

are as follows (18) Initially time locations for Q R and S wave peaks were

determined by delineation and denoted by nQ nR and nS Beats for which no R wave

peak was present were rejected from the analysis If the delineator determined an R

wave peak but could not determine a Q- or S-wave peak a second search was

undertaken A Q wave - and S wave peak were identified as corresponding to the

lowest signal amplitude in the time window of 2 ms after QRS onset to 2 ms prior to

the R wave peak and 2 ms after R wave peak to 2 ms before the QRS offset

respectively The time instants for the maximum absolute derivative of the slopes

between the Q and R wave peaks and between the R and S wave peaks nU and nD

respectively were determined Then a line was fitted in the least squares sense to

the ECG signal in a window of 8 ms centered around the time of each of the

8

maximum absolute derivatives nU and nD so as to generate a slope for that particular

sequence of the QRS complex Only in leads V1-V3 with a typical S wave peak

below baseline a third slope was measured by fitting a line to the ECG signal in a

window centered around the maximal derivative nT of the ECG between the S-wave

peak nS and the end of the QRS complex nOFF Leads other than V1-V3 with

measurable TS in some patients have not been considered due to the low statistical

value derived from the measurement For beats where the 8-ms window centered at

points nU nD and nT was not fully present inside its corresponding limits [nQ nR] [nR

nS] and [nS nOFF] respectively the associated slope measurement was rejected In

those cases where the S wave disappeared during ischemia evolution in the involved

leads (V1-V3) the TS slope measurement was not evaluated for the successive

beats after that time instant One example of the evolution of the US DS and TS

changes is shown in Figure 1b as well as representative beats at the beginning and

end of the PCI procedure respectively

Calculation of the QRS slope changes during PCI

To quantify the total amount of change of the QRS slopes due to the ischemia at the

end of the PCI procedure the change (labeled ∆USPCI and ∆DSPCI) were computed

for each of the 12 leads for each patient First the dynamic QRS slope measures for

all beats involved from the onset of the occlusion (t = 0) and until the end t = tPCI

were blockwise averaged in subsets of 8 beats Then a line was fitted over these

averaged values in a least square sense Subsequently the change ∆αPCI (α = US or

DS) was defined as the product of the slope ℓ of the resulting fitted line and the total

duration tPCI of the PCI process and denoted by ∆αPCI = ℓ tPCI(17) This fitting

strategy was used to reduce the effect of possible outlier measurements on ∆αPCI A

9

graphic representation of this strategy is shown in Figure 2 Among all 12 leads the

maximal positive delta of the DS deflection (positive change- DS slope getting less

steep) and maximal negative change of the US deflection (negative change- US

slope getting less steep) was determined for each patient The sum of all positive

delta change of the DS deflection and negative change of the US deflection was

calculated as to quantify the changes

R-wave amplitude- and QRS duration analysis

R- and S wave amplitudes were automatically measured using the PR interval as the

isoelectric level Delta changes of the R- and S-wave amplitudes (∆RaPCI and ∆SaPCI)

were determined in the same way as that used for the QRS slopes in each lead at

the end of the PCI recording The QRS duration was determined by taking a global

measurement from the standard 12 leads In each beat the earliest QRS onset and

the latest QRS offset among the 12 leads were selected as the beginning and end

respectively of the depolarization phase taken as the longest temporal projection for

the electrical activity of the depolarization In addition a multilead detection rule was

applied to reduce the risk of misestimation for example due to large simultaneous ST-

segment deviation or noise (22) In brief with this multilead detection rule the earliest

mark of the QRS onset and the latest mark of the QRS end respectively in any of

the 12 leads were accepted only if they did not differ from the three closest

corresponding marks in other leads by more than 6 and 10 ms respectively for each

beat The automatically determined QRS onset and end were also manually

validated with no disagreement about the delineations between the two methods

Finally the delta of the QRS duration ∆QRSDPCI was determined using the same

methodology applied for the above indices

10

ST segment analysis

ST segment measurements were made automatically in each lead at the ST-J point

using the PR interval as the isoelectric level Absolute ST deviation ∆STPCI at the end

of the PCI recording relative to the ST level at rest was determined for each lead In

addition the maximal ST elevation and sum of ST elevation (positive values for

∆STPCI) among all leads at the end of the PCI recording were determined for each

patient

Acquisition of radionuclide images

Approximately 30 mCi (1100 MBq) of sestamibi was injected intravenously in each

patient after confirmation of total coronary artery occlusion by the balloon The

scintigraphic imaging carried out by a single-head rotating gamma camera (Elscint

Haifa Israel) was obtained within 3 hours after completion of the PCI procedure The

acquisitions were made with a high-resolution collimator in a 64x64 matrix 69 mm

pixel size using 30 projections (25sprojection) over 180deg (from 45deg right anterior

oblique to 45deg left posterior oblique) Using filtered backprojection with a Butterworth

filter transverse sections were reconstructed without attenuation correction Short

axis sections were reconstructed for further analysis (23)

For the control study another injection of ~ 30 mCi (1110 MBq) 99m Tc-sestamibi

was administered and imaging was performed 2-3 hours later with the same gamma

11

camera and acquisition protocol as for the PCI study All patients were clinically

stable between the two examinations

Evaluation of radionuclide images

The Cedars-Sinai and Emory quantitative analysis program (CEqual ADAC

Laboratories Milpitas California) (24 25) was used for making volume-weighted

bullacutes eye plots from the short-axis slices Any loss of perfusion during the PCI study

compared to the control study was determined by an automatic procedure by

comparing the bullacutes eye plot of the 2 studies for each patient (23) and expressed as

both extent and severity of the myocardial ischemia as described earlier (14)

Reduction of perfusion by 25 or more was used as the threshold for indicating

significantly hypoperfused myocardium (23) This area in the bullacutes eye plot was

delineated as an ldquoextent maprdquo representing all added slices (or volume) of the left

ventricular (LV) myocardium expressed as a percentage of the LV and defining the

extent of ischemia The total pixel count difference (or local perfusion loss) between

the control and occlusion study within this delineated hypoperfused area in the

ldquoextent maprdquo was the severity and expressed as a percentage of the total pixel count

in the control situation within the same area (23) The extent and severity of the

ischemia were calculated for each patient All the scintigraphic data analysis was

performed at the Department of Clinical Physiology Lund University Sweden

blinded to the ECG data

Statistical Methods

12

Results are presented as meanplusmn one standard deviation Due to the small number of

patients in the study nonparametric tests were used Spearman rank correlation

coefficient (r) was used for correlation analysis Mann-Whitney U test was used for

comparison between groups Multiple linear regression analysis was used to evaluate

additional value of different QRS changes to ST changes in predicting the amount of

ischemia All these variables were considered continuous All statistical tests were

two-sided and significance was defined as plt005 The statistical analysis was

performed by SPSS version 150 for Windows

RESULTS

Myocardial scintigraphy

The extent and severity of the ischemia produced by the coronary occlusion by PCI

as estimated by myocardial scintigraphy are presented in Table 1 for all patients and

subgroups based on occluded artery Among all patients the extent varied between 0

and 65 of the left ventricle (mean 20plusmn17) and the severity between 26 and 63

(mean 38plusmn8)

QRS slopes (US DS and TS)

In Figure 3 the meanSD of the QRS slope changes for LAD (anterior leads) and

RCA occlusions (inferior leads) are shown respectively The change of US and DS

was statistically different in leads V2-V4 and in II aVF and III for the two separate

ischemia locations whereas the difference between DS and TS change in the LAD

group was non-significant The amount of slope change was greater in the LAD

group than in the RCA group in general In Figure 4 the changes of DS during the

13

PCI are shown among all 12 leads for patients with LAD LCX and RCA occlusions

respectively The spatial distribution of DS change was most evident for anterior and

inferior ischemia with most marked changes in leads V2 to V5 and leads II aVF and

III respectively In the LCX group the most pronounced changes were noted in leads

V5 and aVL Due to the present finding of TS being less or equally affected by the

ischemia compared to DS as in our previous study with a larger population (18) and

the variable presence of S-waves in most leads except from V1-V3 only US and DS

were considered in the following correlation analysis

Correlation between depolarization changes and ischemia

R-wave downslope (DS) change

DS changes at the end of the PCI were found to be positive in 299 (66) of the total

analyzed leads by 148 182 (01-1249) μVms and negative in 157 (34) leads

by 86112 (0-588) μVms The quantitative distribution among the patients of the

maximum positive DS change in any lead sum of all positive DS change as well as

sum of all DS change regardless of direction respectively are presented in Table 2a

Additionally the correlation between the different quantifications of DS change and

the extent and severity of ischemia is shown For all DS measures there were

significant correlations to the amount of ischemia with the highest Spearman rank

correlation coefficient found for sum of positive DS change among all 12 leads

(r=071 plt00001 for extent and r=073 plt00001 for severity)

R-wave upslope (US) change

At the end of the PCI the US showed a negative mean change by 76plusmn102 (0-942)

μVms in 301 (66) leads whereas 155 leads (34) presented a positive change by

78plusmn131 (0-94) μVms In Table 2b the correlation between corresponding

14

quantifications of US change and amount of ischemia are presented as well as the

distribution of the different patient specific US measures A comparison between US

change and DS change with respect to correlation to ischemia is presented in Figure

5 where the DS change shows the strongest correlation

R- wave amplitude change

The R wave amplitude at the end of the PCI decreased in 284 (62) leads by

11531287 (07-8519) μV and increased by 1205 1588 (02-8663) μV in 172

(38) of the total analyzed leads In Table 2c the Spearman rank correlation

coefficients are presented regarding the correlation between R-wave amplitude

changes (sum of all R-wave increase and decrease and sum of all R-wave changes

among the leads respectively) and the measures of ischemia All correlations were

significant with the sum of total R-wave amplitude change among all leads showing

the highest correlation coefficient (r=063 plt00001 and r=060 plt00001 for extent

and severity respectively) In the same panel also the distribution of the R-wave

measures among the subjects is displayed

QRS duration change

At the end of the PCI 24 patients (63) showed a prolongation of the QRS duration

whereas 14 patients (37) showed a decrease as displayed in Table 2d For both

subgroups the correlation between delta QRS duration change and the amount of

ischemia was very weak and non-significant

ST-segment analysis

The maximal ST elevation in any lead and the summed ST elevation among all 12

leads are presented in Table 3 with the largest changes in the LAD group followed

15

by the LCX and RCA group respectively The correlation between maximal ST

elevation and extent and severity of ischemia was r=073 plt00001 for both

ischemia measures The corresponding correlation for summed ST elevation was

r=067 plt00001 and r=073 plt00001 for extent and severity respectively

Association between QRS slope and ST segment changes

The correlation between QRS slope changes (US and DS) and ST-segment change

considering both maximum ST elevation and sum of ST elevation is presented in

Figure 6 The correlation between DS change and maxsum ST elevation was

stronger than that of US (r=075 and r=069 respectively for DS compared to

r=044 and r=061 for US) all highly significant

Regression analysis

To evaluate if depolarization changes provide information to predict the extent and

severity of the ischemia in addition to the conventional ST elevation analysis a

multiple linear regression analysis was performed The results are displayed in Table

4 where US and DS provided the largest increase above and beyond that of the ST

segment Regarding the extent of ischemia the portion of the dependent variable

explained by the independent variables R2 increased by 129 after adding US and

by 122 after adding DS A combination of the two increased the prediction of

extent by 145 The corresponding values for the severity of ischemia were 40

71 and 71 respectively The additive effect of R-wave amplitude change was

lower

16

DISCUSSION

The main finding in our study was that changes in the downward slope of the R wave

(DS) significantly correlate to both the extent and severity of ischemia The

correlation coefficient was higher than that between conventional QRS parameters

and ischemia and similar to that of ST elevation Sum of positive DS change among

all leads showed higher correlation coefficients than other QRS slope quantifications

DS change correlated to simultaneous ST elevation but also gave separate additive

predictive information about the amount of ischemia beyond that provided by

conventional ST-segment changes alone

The severity of ischemia and hence risk of fast development of irreversible

myocardial necrosis due to a sudden total coronary occlusion depends on a number

of local factors such as the presence of collaterals and ability of the myocardium to

adapt to anaerobic metabolism (pre-conditioning) Fast development of new acute

treatment regimens for STEMI (more aggressive anti-platelet therapy and especially

invasive strategies with primary PCI) have improved clinical outcome It has

however also resulted in a higher number of referrals to more remotely located PCI

centers as well as early often pre-hospital ECG-based triage Using as much

information as possible from the index standard 12-lead ECG is essential for early

ischemia detection risk stratification based on ischemia severity assessment as well

as prediction of outcome

In addition to ST-T changes caused by the injury current more severe ischemia

affects the myocytes and conduction system thus slowing down the conduction and

affecting the depolarization phase of the ECG Localized conduction delay may lead

to the loss of cancellation effects from opposite electrical forces changing the QRS-

17

wave amplitudes and slightly increasing the QRS duration Depolarization changes

are more challenging than ST-T changes to measure and quantify

In this study we apply a new robust method to evaluate changes of the slopes in the

QRS complex in a well defined situation of ischemia due to coronary occlusion We

have previously shown DS to be more sensitive to ischemia than the US in a larger

patient population (18) using the same ischemia model In addition we found that the

upslope of the S wave (TS) in leads V1-V3 showed equal information to the DS

Although the DS in different leads represents different timing during the

depolarization phase we here show its dynamic change as a sum of all leads to

correlate to the amount of ischemia and also display lead specific spatial information

with respect to coronary occlusion site

In the Sclarovsky-Birnbaum ischemia grading system loss of antero-septal S-waves

during anterior STEMI and changes in the R-wave amplitudeST-J point ratio in

inferior STEMI respectively indicate more severe ischemia less salvage worse

microvascular flow failure of ST-segment resolution and worse prognosis (8 10 11)

In a canine model of ischemia QRS prolongation was a sign of less myocardial

protection and more severe ischemia (5)

The QRS slope changes and especially changes in the downward slope of the R

wave (DS) evaluated in the present study represent variations in the R- and S-wave

amplitudes as well as changes in the total depolarization duration The slope

measurement is not affected by simultaneous ST elevation and J-point drift making it

stable to calculate In this study there was a correlation between the ST elevation and

the sum of DS change however not high enough implying they are due to exactly the

same pathogenesis but instead suggesting DS to be influenced by reduced

conduction due to the ischemia By regression analysis we also found the DS change

18

to add another 12 and 7 respectively for predicting the extent and severity of

ischemia quantified by myocardial scintigraphy although this is observed after just 5

minutes of ischemia It could be hypothesized that longer ischemia duration would

produce even more pronounced depolarization changes in addition to ST changes

Therefore it is plausible to suggest that depolarization analysis presented by DS

change could add relevant information about the severity of ischemia in addition to

the conventional ST-T analysis

Limitations

The study population is small and therefore the statistical finding must be interpreted

with this in mind This human model of about 5 minutes of controlled ischemia by PCI

with myocardial scintigraphy as gold standard is unique Nevertheless it just

represents the first few minutes of ischemia and the method should also be applied to

situations with longer periods of ischemia where even more severe grades of

ischemia could be expected possibly affecting the QRS complex more This method

is applied on continuous ECG recordings with calculations of dynamic changes and

is suitable for sequential ECGs recorded in a monitoring situation rather than a ldquosnap-

shotrdquo ECG without known baseline values

Conclusion

QRS slope analysis allows quantification of depolarization changes during ischemia

R-wave downslope (DS) demonstrate dynamic changes during coronary artery

occlusion that correlate to the extent and severity of the ischemia assessed by

myocardial scintigraphy Furthermore it provides information beyond that given by

conventional ST-segment analysis suggesting its potential value in risk stratification

of patients with acute coronary syndrome

19

Acknowledgements

This study is a part of the STAFF Studies Investigations

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10Wolak A Yaroslavtsev S Amit G Birnbaum Y Cafri C Atar S Gilutz H Ilia R

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B Electrocardiographic classification of acute myocardial ischemia Isr J Med Sci

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13Pettersson J Pahlm O Carro E Edenbrandt L Ringborn M Sornmo L Warren

SG Wagner GS Changes in high-frequency QRS components are more sensitive

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21

14Ringborn M Pettersson J Persson E Warren SG Platonov P Pahlm O Wagner

GS Comparison of high-frequency QRS components and ST-segment elevation to

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16Wagner NB Sevilla DC Krucoff MW Lee KL Pieper KS Kent KK Bottner RK

Selvester RH Wagner GS Transient alterations of the QRS complex and ST

segment during percutaneous transluminal balloon angioplasty of the left anterior

descending coronary artery Am J Cardiol 1988 62(16)1038-1042

17Pueyo E Sornmo L Laguna P QRS slopes for detection and characterization of

myocardial ischemia IEEE Trans Biomed Eng 2008 55(2 Pt 1)468-477

18Romero D Ringborn M Laguna P Pahlm O Pueyo E Depolarization Changes

During Acute Myocardial Ischemia by Evaluation of QRS Slopes Standard Lead and

Vectorial Approach IEEE Trans Biomed Eng 2011 58(1)110-120

19Haronian HL Remetz MS Sinusas AJ Baron JM Miller HI Cleman MW Zaret

BL Wackers FJ Myocardial risk area defined by technetium-99m sestamibi imaging

during percutaneous transluminal coronary angioplasty comparison with coronary

angiography J Am Coll Cardiol 1993 22(4)1033-1043

20Gibbons RJ Verani MS Behrenbeck T Pellikka PA OConnor MK Mahmarian

JJ Chesebro JH Wackers FJ Feasibility of tomographic 99mTc-hexakis-2-methoxy-

2-methylpropyl-isonitrile imaging for the assessment of myocardial area at risk and

the effect of treatment in acute myocardial infarction Circulation 1989 80(5)1277-

1286

22

21Mason RE Likar I A new system of multiple-lead exercise electrocardiography

Am Heart J 1966 71(2)196-205

22Laguna P Jane R Caminal P Automatic detection of wave boundaries in

multilead ECG signals validation with the CSE database Comput Biomed Res 1994

27(1)45-60

23Persson E Palmer J Pettersson J Warren SG Borges-Neto S Wagner GS

Pahlm O Quantification of myocardial hypoperfusion with 99m Tc-sestamibi in

patients undergoing prolonged coronary artery balloon occlusion Nucl Med Commun

2002 23(3)219-228

24Garcia EV Cooke CD Van Train KF Folks R Peifer J DePuey EG Maddahi J

Alazraki N Galt J Ezquerra N et al Technical aspects of myocardial SPECT

imaging with technetium-99m sestamibi Am J Cardiol 1990 66(13)23E-31E

25Persson E Pettersson J Ringborn M Sornmo L Warren SG Wagner GS

Maynard C Pahlm O Comparison of ST-segment deviation to scintigraphically

quantified myocardial ischemia during acute coronary occlusion induced by

percutaneous transluminal coronary angioplasty Am J Cardiol 2006 97(3)295-300

23

Legends to Figures

Figure 1

a Beat example showing the delineation marks used to evaluate the QRS slopes

nON = QRS onset nQ nR and nS = time locations for the Q R and S wave peaks

respectively nU= maximum derivative between nQ and nR nD = maximum derivative

between nR and nS nT = maximum absolute derivative between nS and nOFF nOFF=

QRS offset

b Temporal evolution of the US DS and TS for a particular ECG recording during

the PCI procedure Initial and final beat of the recording are additionally plotted to

show how they link to the corresponding slope measurements

US= upward slope of the R wave DS= downward slope of the R wave TS= upward

slope of the S wave

Figure 2 Representation of the strategy by which a line is fitted to the averaged DS

values during the PCI procedure in a least square sense to reduce the effect of

possible outlier measurements on the DS change computation

DS= downward slope of the R wave

Figure 3 MeanSD of the QRS slope changes for LAD (leads V1-V6) and RCA

occlusions (leads II aVF and III) TS changes are shown only for leads V1-V3 in the

LAD group


slope of the S wave

24

Figure 4 Spatial distribution of DS changes among the 12 leads for the LAD LCX

and RCA subgroups respectively


Figure 5 Correlation between QRS slope changes (US and DS) and amount of

ischemia (extent and severity) DS- dashed line

US= upward slope of the R wave DS= downward slope of the R wave LV= left

ventricle

Figure 6 Correlation between QRS slope changes (US and DS) and ST elevation

DS- dashed line

US= upward slope of the R wave DS= downward slope of the R wave sum US

(neg)= sum of negative US change in all leads at the end of PCI sum DS (pos)= sum

of positive DS change in all leads at the end of PCI sum ST el = sum of ST elevation

in all leads at the end of PCI max ST el= maximal ST elevation in any lead at the

end of PCI

Table 1 Myocardial ischemia during PCI expressed as extent and severity in the total study population and subgroups based on coronary artery occluded LV = left ventricle

Coronary artery occluded

Extent ( of LV) MeanplusmnSD (range)

Severity () MeanplusmnSD (range)

Total (n=38) 20plusmn17 (0-65) 38plusmn8 (26-63)

LAD (n=8) 43plusmn15 (15-65) 47plusmn9 (33-63)

LCX (n=9) 19plusmn14 (4-45) 35plusmn5 (29-43)

RCA (n=21) 12plusmn10 (01-32) 35plusmn7 (26-51)

Table 2 Quantitative distribution of the depolarization changes A) DS change B) US change C) R wave amplitude change and D) QRS duration change as well as their correlation to ischemia (Spearman rank correlation) DS= downward slope of the R wave US= upward slope of the R wave Ra= R wave amplitude LV = left ventricle

QRS parameter MeanplusmnSD (range) Extent ( of LV)

(r p) Severity ()

(r p)

A) DS (Vms)

Max pos DS change 35plusmn28 (3-125) 060 lt00001 058 00001

Sum pos DS change 116plusmn97 (8-125) 071 lt00001 073 lt00001

Sum tot DS change 154plusmn114 (17-552) 062 lt00001

062 lt00001

B) US (Vms)

Max neg US change 15plusmn13 (09-54)

050 00015

047 00032

Sum neg US change 60plusmn60 (1-295)

062 lt00001

055 00004

Sum total US change 92plusmn74 (16-319)

039 00155

033 00390

C) R-wave (V)

Sum Ra increase 701plusmn862 (39-3291) 041 00110 046 00040

Sum Ra decrease 871plusmn811 (79-3668) 052 00010 045 00040

Sum tot Ra change 1574plusmn1377 (190-6291) 063 lt00001 060 lt00001 D) QRS (ms)

QRS widening (n=24) 84plusmn66 (0-23) 017 NS 030 NS

QRS narrowing (n=14) 40plusmn50 (03-171) 039 NS 028 NS

Table 3 Delta changes of ST-J from t=0 to the end of the PCI expressed as the maximum ST elevation in any of the 12 leads and the sum of ST-elevation among all leads (V)

ECG parameter LAD

RCA

LCX

Max ST elevation (V) 567 459(25-1384) 150 133(0-486)

214 239(18-727)

Sum ST elevation (V) 1622 1514(36-4858) 520 561(0-1979) 552 540(52-1557)

Table 4 Multiple regression analysis Prediction of extent and severity of ischemia by adding of QRS slope (US andor DS in Vms) or R wave amplitude changes (V) to sum of ST elevation (mV) US= upward slope of the R wave DS= downward slope of the R wave Ra= R wave amplitude Ra sum negpos= Sum of the decreaseincrease of Ra among all leads Ra sum tot = Sum of all changes in Ra among all leads LV= left ventricle arrow increase of the explanation of the dependent variable by the added independent variables Predictor variables

Dependent Extent of ischemia ( of LV) R2 p

variable Severity of ischemia ( of LV) R2 p

ST 0593 lt00001 0665 lt00001

ST US 0722 lt00001 uarr 129 0705 lt00001 uarr 40

ST DS 0715 lt00001 uarr 122 0736 lt00001 uarr 71

ST DS US 0738 lt00001 uarr 145 0736 lt00001 uarr 71

ST Ra sum neg 0688 lt00001 uarr 95 0693 lt00001 uarr 28

ST Ra sum pos 0593 lt00001 uarr 00 0669 lt00001 uarr 04

ST Ra sum tot 0644 lt00001 uarr 51 0673 lt00001 uarr 08

Take down policyIf you believe that this document breaches copyright please contact us providing details and we will removeaccess to the work immediately and investigate your claim

Download date 26 Aug 2018

1





Platonov MD PhD ab







Center Durham NC










Phone +46 455 73 10 00 Fax number +46 455 73 65 80

2


ABSTRACT

















deviation PCI

3

INTRODUCTION























4














changes












5











were to test




prolongation)




METHODS

Study population




6











ECG Acquisition












myocardium

7








QRS slope analysis

















8

























9

























10

ST segment analysis






patient













11





















Statistical Methods

12









RESULTS






(mean 38plusmn8)








13

























14
















QRS duration change





ST-segment analysis



15











Regression analysis










lower

16

DISCUSSION
























17


























18








Limitations










Conclusion







19

Acknowledgements


References





















Am Coll Cardiol 1997 30(2)452-458

20





















1990 26(9)525-531




Cardiol 2000 36(6)1827-1834

21
























1286

22


Am Heart J 1966 71(2)196-205



27(1)45-60




2002 23(3)219-228








23

Legends to Figures

Figure 1





QRS offset





slope of the S wave







LAD group


slope of the S wave

24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001







1





Platonov MD PhD ab







Center Durham NC










Phone +46 455 73 10 00 Fax number +46 455 73 65 80

2


ABSTRACT

















deviation PCI

3

INTRODUCTION























4














changes












5











were to test




prolongation)




METHODS

Study population




6











ECG Acquisition












myocardium

7








QRS slope analysis

















8

























9

























10

ST segment analysis






patient













11





















Statistical Methods

12









RESULTS






(mean 38plusmn8)








13

























14
















QRS duration change





ST-segment analysis



15











Regression analysis










lower

16

DISCUSSION
























17


























18








Limitations










Conclusion







19

Acknowledgements


References





















Am Coll Cardiol 1997 30(2)452-458

20





















1990 26(9)525-531




Cardiol 2000 36(6)1827-1834

21
























1286

22


Am Heart J 1966 71(2)196-205



27(1)45-60




2002 23(3)219-228








23

Legends to Figures

Figure 1





QRS offset





slope of the S wave







LAD group


slope of the S wave

24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001







2


ABSTRACT

















deviation PCI

3

INTRODUCTION























4














changes












5











were to test




prolongation)




METHODS

Study population




6











ECG Acquisition












myocardium

7








QRS slope analysis

















8

























9

























10

ST segment analysis






patient













11





















Statistical Methods

12









RESULTS






(mean 38plusmn8)








13

























14
















QRS duration change





ST-segment analysis



15











Regression analysis










lower

16

DISCUSSION
























17


























18








Limitations










Conclusion







19

Acknowledgements


References





















Am Coll Cardiol 1997 30(2)452-458

20





















1990 26(9)525-531




Cardiol 2000 36(6)1827-1834

21
























1286

22


Am Heart J 1966 71(2)196-205



27(1)45-60




2002 23(3)219-228








23

Legends to Figures

Figure 1





QRS offset





slope of the S wave







LAD group


slope of the S wave

24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001







3

INTRODUCTION























4














changes












5











were to test




prolongation)




METHODS

Study population




6











ECG Acquisition












myocardium

7








QRS slope analysis

















8

























9

























10

ST segment analysis






patient













11





















Statistical Methods

12









RESULTS






(mean 38plusmn8)








13

























14
















QRS duration change





ST-segment analysis



15











Regression analysis










lower

16

DISCUSSION
























17


























18








Limitations










Conclusion







19

Acknowledgements


References





















Am Coll Cardiol 1997 30(2)452-458

20





















1990 26(9)525-531




Cardiol 2000 36(6)1827-1834

21
























1286

22


Am Heart J 1966 71(2)196-205



27(1)45-60




2002 23(3)219-228








23

Legends to Figures

Figure 1





QRS offset





slope of the S wave







LAD group


slope of the S wave

24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001







4














changes












5











were to test




prolongation)




METHODS

Study population




6











ECG Acquisition












myocardium

7








QRS slope analysis

















8

























9

























10

ST segment analysis






patient













11





















Statistical Methods

12









RESULTS






(mean 38plusmn8)








13

























14
















QRS duration change





ST-segment analysis



15











Regression analysis










lower

16

DISCUSSION
























17


























18








Limitations










Conclusion







19

Acknowledgements


References





















Am Coll Cardiol 1997 30(2)452-458

20





















1990 26(9)525-531




Cardiol 2000 36(6)1827-1834

21
























1286

22


Am Heart J 1966 71(2)196-205



27(1)45-60




2002 23(3)219-228








23

Legends to Figures

Figure 1





QRS offset





slope of the S wave







LAD group


slope of the S wave

24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001







5











were to test




prolongation)




METHODS

Study population




6











ECG Acquisition












myocardium

7








QRS slope analysis

















8

























9

























10

ST segment analysis






patient













11





















Statistical Methods

12









RESULTS






(mean 38plusmn8)








13

























14
















QRS duration change





ST-segment analysis



15











Regression analysis










lower

16

DISCUSSION
























17


























18








Limitations










Conclusion







19

Acknowledgements


References





















Am Coll Cardiol 1997 30(2)452-458

20





















1990 26(9)525-531




Cardiol 2000 36(6)1827-1834

21
























1286

22


Am Heart J 1966 71(2)196-205



27(1)45-60




2002 23(3)219-228








23

Legends to Figures

Figure 1





QRS offset





slope of the S wave







LAD group


slope of the S wave

24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001







6











ECG Acquisition












myocardium

7








QRS slope analysis

















8

























9

























10

ST segment analysis






patient













11





















Statistical Methods

12









RESULTS






(mean 38plusmn8)








13

























14
















QRS duration change





ST-segment analysis



15











Regression analysis










lower

16

DISCUSSION
























17


























18








Limitations










Conclusion







19

Acknowledgements


References





















Am Coll Cardiol 1997 30(2)452-458

20





















1990 26(9)525-531




Cardiol 2000 36(6)1827-1834

21
























1286

22


Am Heart J 1966 71(2)196-205



27(1)45-60




2002 23(3)219-228








23

Legends to Figures

Figure 1





QRS offset





slope of the S wave







LAD group


slope of the S wave

24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001







7








QRS slope analysis

















8

























9

























10

ST segment analysis






patient













11





















Statistical Methods

12









RESULTS






(mean 38plusmn8)








13

























14
















QRS duration change





ST-segment analysis



15











Regression analysis










lower

16

DISCUSSION
























17


























18








Limitations










Conclusion







19

Acknowledgements


References





















Am Coll Cardiol 1997 30(2)452-458

20





















1990 26(9)525-531




Cardiol 2000 36(6)1827-1834

21
























1286

22


Am Heart J 1966 71(2)196-205



27(1)45-60




2002 23(3)219-228








23

Legends to Figures

Figure 1





QRS offset





slope of the S wave







LAD group


slope of the S wave

24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001







8

























9

























10

ST segment analysis






patient













11





















Statistical Methods

12









RESULTS






(mean 38plusmn8)








13

























14
















QRS duration change





ST-segment analysis



15











Regression analysis










lower

16

DISCUSSION
























17


























18








Limitations










Conclusion







19

Acknowledgements


References





















Am Coll Cardiol 1997 30(2)452-458

20





















1990 26(9)525-531




Cardiol 2000 36(6)1827-1834

21
























1286

22


Am Heart J 1966 71(2)196-205



27(1)45-60




2002 23(3)219-228








23

Legends to Figures

Figure 1





QRS offset





slope of the S wave







LAD group


slope of the S wave

24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001







9

























10

ST segment analysis






patient













11





















Statistical Methods

12









RESULTS






(mean 38plusmn8)








13

























14
















QRS duration change





ST-segment analysis



15











Regression analysis










lower

16

DISCUSSION
























17


























18








Limitations










Conclusion







19

Acknowledgements


References





















Am Coll Cardiol 1997 30(2)452-458

20





















1990 26(9)525-531




Cardiol 2000 36(6)1827-1834

21
























1286

22


Am Heart J 1966 71(2)196-205



27(1)45-60




2002 23(3)219-228








23

Legends to Figures

Figure 1





QRS offset





slope of the S wave







LAD group


slope of the S wave

24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001







10

ST segment analysis






patient













11





















Statistical Methods

12









RESULTS






(mean 38plusmn8)








13

























14
















QRS duration change





ST-segment analysis



15











Regression analysis










lower

16

DISCUSSION
























17


























18








Limitations










Conclusion







19

Acknowledgements


References





















Am Coll Cardiol 1997 30(2)452-458

20





















1990 26(9)525-531




Cardiol 2000 36(6)1827-1834

21
























1286

22


Am Heart J 1966 71(2)196-205



27(1)45-60




2002 23(3)219-228








23

Legends to Figures

Figure 1





QRS offset





slope of the S wave







LAD group


slope of the S wave

24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001







11





















Statistical Methods

12









RESULTS






(mean 38plusmn8)








13

























14
















QRS duration change





ST-segment analysis



15











Regression analysis










lower

16

DISCUSSION
























17


























18








Limitations










Conclusion







19

Acknowledgements


References





















Am Coll Cardiol 1997 30(2)452-458

20





















1990 26(9)525-531




Cardiol 2000 36(6)1827-1834

21
























1286

22


Am Heart J 1966 71(2)196-205



27(1)45-60




2002 23(3)219-228








23

Legends to Figures

Figure 1





QRS offset





slope of the S wave







LAD group


slope of the S wave

24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001







12









RESULTS






(mean 38plusmn8)








13

























14
















QRS duration change





ST-segment analysis



15











Regression analysis










lower

16

DISCUSSION
























17


























18








Limitations










Conclusion







19

Acknowledgements


References





















Am Coll Cardiol 1997 30(2)452-458

20





















1990 26(9)525-531




Cardiol 2000 36(6)1827-1834

21
























1286

22


Am Heart J 1966 71(2)196-205



27(1)45-60




2002 23(3)219-228








23

Legends to Figures

Figure 1





QRS offset





slope of the S wave







LAD group


slope of the S wave

24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001







13

























14
















QRS duration change





ST-segment analysis



15











Regression analysis










lower

16

DISCUSSION
























17


























18








Limitations










Conclusion







19

Acknowledgements


References





















Am Coll Cardiol 1997 30(2)452-458

20





















1990 26(9)525-531




Cardiol 2000 36(6)1827-1834

21
























1286

22


Am Heart J 1966 71(2)196-205



27(1)45-60




2002 23(3)219-228








23

Legends to Figures

Figure 1





QRS offset





slope of the S wave







LAD group


slope of the S wave

24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001







14
















QRS duration change





ST-segment analysis



15











Regression analysis










lower

16

DISCUSSION
























17


























18








Limitations










Conclusion







19

Acknowledgements


References





















Am Coll Cardiol 1997 30(2)452-458

20





















1990 26(9)525-531




Cardiol 2000 36(6)1827-1834

21
























1286

22


Am Heart J 1966 71(2)196-205



27(1)45-60




2002 23(3)219-228








23

Legends to Figures

Figure 1





QRS offset





slope of the S wave







LAD group


slope of the S wave

24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001







15











Regression analysis










lower

16

DISCUSSION
























17


























18








Limitations










Conclusion







19

Acknowledgements


References





















Am Coll Cardiol 1997 30(2)452-458

20





















1990 26(9)525-531




Cardiol 2000 36(6)1827-1834

21
























1286

22


Am Heart J 1966 71(2)196-205



27(1)45-60




2002 23(3)219-228








23

Legends to Figures

Figure 1





QRS offset





slope of the S wave







LAD group


slope of the S wave

24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001







16

DISCUSSION
























17


























18








Limitations










Conclusion







19

Acknowledgements


References





















Am Coll Cardiol 1997 30(2)452-458

20





















1990 26(9)525-531




Cardiol 2000 36(6)1827-1834

21
























1286

22


Am Heart J 1966 71(2)196-205



27(1)45-60




2002 23(3)219-228








23

Legends to Figures

Figure 1





QRS offset





slope of the S wave







LAD group


slope of the S wave

24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001







17


























18








Limitations










Conclusion







19

Acknowledgements


References





















Am Coll Cardiol 1997 30(2)452-458

20





















1990 26(9)525-531




Cardiol 2000 36(6)1827-1834

21
























1286

22


Am Heart J 1966 71(2)196-205



27(1)45-60




2002 23(3)219-228








23

Legends to Figures

Figure 1





QRS offset





slope of the S wave







LAD group


slope of the S wave

24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001







18








Limitations










Conclusion







19

Acknowledgements


References





















Am Coll Cardiol 1997 30(2)452-458

20





















1990 26(9)525-531




Cardiol 2000 36(6)1827-1834

21
























1286

22


Am Heart J 1966 71(2)196-205



27(1)45-60




2002 23(3)219-228








23

Legends to Figures

Figure 1





QRS offset





slope of the S wave







LAD group


slope of the S wave

24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001







19

Acknowledgements


References





















Am Coll Cardiol 1997 30(2)452-458

20





















1990 26(9)525-531




Cardiol 2000 36(6)1827-1834

21
























1286

22


Am Heart J 1966 71(2)196-205



27(1)45-60




2002 23(3)219-228








23

Legends to Figures

Figure 1





QRS offset





slope of the S wave







LAD group


slope of the S wave

24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001







20





















1990 26(9)525-531




Cardiol 2000 36(6)1827-1834

21
























1286

22


Am Heart J 1966 71(2)196-205



27(1)45-60




2002 23(3)219-228








23

Legends to Figures

Figure 1





QRS offset





slope of the S wave







LAD group


slope of the S wave

24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001







21
























1286

22


Am Heart J 1966 71(2)196-205



27(1)45-60




2002 23(3)219-228








23

Legends to Figures

Figure 1





QRS offset





slope of the S wave







LAD group


slope of the S wave

24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001







22


Am Heart J 1966 71(2)196-205



27(1)45-60




2002 23(3)219-228








23

Legends to Figures

Figure 1





QRS offset





slope of the S wave







LAD group


slope of the S wave

24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001







23

Legends to Figures

Figure 1





QRS offset





slope of the S wave







LAD group


slope of the S wave

24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001







24







ventricle


DS- dashed line





end of PCI











(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001

















(r p) Severity ()

(r p)

A) DS (Vms)




062 lt00001

B) US (Vms)


050 00015

047 00032


062 lt00001

055 00004


039 00155

033 00390

C) R-wave (V)







ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001








ECG parameter LAD

RCA

LCX


214 239(18-727)





ST 0593 lt00001 0665 lt00001










ST 0593 lt00001 0665 lt00001







evaluation of depolarization changes during acute ... · 1 evaluation of depolarization changes...

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